Resistant starch (prebiotic)
What it is
A type of starch that passes through the small intestine undigested and feeds beneficial bacteria in the colon, producing butyrate. A 2024 review of 20 trials found resistant starch significantly improves insulin sensitivity, reduces post-meal blood sugar spikes, and increases satiety. Green bananas, cooked-then-cooled potatoes, and raw potato starch are natural sources. Start with small doses to avoid bloating.
Dose
15–30 g/day from food or supplement (raw potato starch, green banana flour); start low at 5 g/day
Time of day & tips
Start with 5 g/day in the morning in a cold drink or food — heat destroys resistant starch. Gradually increase to 20–40 g/day across meals. Drink plenty of water. Expect bloating in the first 2 weeks.
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